jaguilera100

I've had my rx8 for about three years and I've had this problem that I press the"DSC OFF" button and nothing happens. Any suggestions on what could be wrong?

RarisRX-8

Dirty connector, Drivers side wheel well (remove smaller fender liner) the harness is the same that leads to your fog lights, 2 connectors are right above and to the right of the drivers side oil cooler if you are facing drivers front tire. Clean and put some dielectric grease in there and you should be good.

ZiG

Are the ABS sensors hall effect? the AWD system on my STi used to get pretty cranky if the ABS sensors weren't kept clean. The symptom would be the system detecting wheel slip at low speeds and locking the center diff, leading to tire scrubbing in sharp turns.

7andan8

For me, a broken (shorted) wire to the third brake light, right at the trunk hinge where the wires run up into the trunk lid. Many years of opening & closing the trunk I guess.

Great thread.

vasquez469

Thank you for the reset process. It was very helpful.

blackpanthertcrf

Given our experience today with both the engine warning light and the dcs/tcs lights staying on I would add to the thread just in case it proved helpful to others.

There were no other lights lit but the above two.

We have a Mazda 6 sport 2.0 diesel built 2006 and today the above lights came on and stayed on, bit of a panic as it was evening and we were 30 miles from home.

Weather was 0C and getting colder, it was also damp and starting to freeze.

When we got home we did some hunting and found this thread, starting at the top we began to work our way down.

Happily we didn't have to go any further than the reset instructions, apart from checking the fuel cap and checking brake lights.

We did the reset and (fingers crossed) for the moment it has switched both the engine light out and the dcs/tcs light out as well, I can only assume it may have been to do with the cold weather.

Although we have had the car over 12 months because of hubby's health issues we never go out when cold especially when its near freezing so this is the first time we have done this.

The car seems to be running perfectly no missing, cutting out etc so was quite puzzled by the engine light coming on, again can only assume cold weather to be the problem.


I can't say thank you enough for starting this thread and giving out the helpful hints you have :-)

crottycat

Someone help, I am having a problem where my Brake light, powersteering light and abs light are on and my speedometer is out. Someone times when i randomly start my car after its just sitting for awhile the speedometer will come back on for alittle bit or go off and on a few times and the other lights will also randomly flash off an on. Can anyone help? I have 2 different brands of tires on but they are the same size. I don't really think because of the symptoms its related to that.

The1

Hey man I had the same problem, it was a 3rd Brake light short. Check the connections that come out of the left side of the trunk while open (in the little bay that the trunk arms collapse into). Really stupid problem and Mazda really blew it with the electrical on this car. Good luck!

Supra1jz

had no brake lights pulled switch and it was working, reinstalled switch and lights would not illuminate. changed the switch now they work when installed to the peddle.

the springs inside the switch were dirty and gummed after cleaning them the smaller one broke, the new brake switch has a design update as well so i think it benefits to change the switch 173k on my r. third brake light wasn't working but realized their was a brake in the wiring leading to it

Gyro_Bot

https://www.rx8club.com/series-i-tro...-light-210916/

Here is a similar thread - however it IS describing EXACTLY what I am noticing.

Gyro_Bot

First of all... both my tail lights are not working, in combination with this issue. So I need to find a solution for this fast, because without working tail lights, that kinda puts my life in danger. Looks like I will be using hand signals for braking.

Is this a electical problem somewhere causing a short and the brake lights dont turn on, and there for the ABS DCS/TCS light come on? - for safety?

Or is this the opposite? the brake lights not working because of a short / fuse or mechanical issue? - probably much less likely.

The ABS DCS/TCS light come on when I brake. They disappear when I turn off the car and then turn it back on.

As soon as I press brake the ABS DCS/TCS light come on.
THESE SYMPTOMS OCCUR WHEN THE CAR IS TURNED ON - EVEN When the car is NOT RUNNING.


What's different?

NOTHING.

I have been driving my car for a very long time with no issues. I have 275 wide tires and racing beat sway bars. All tires are the same pressure. Tread wear is near replacement though.

Things have been perfectly fine.

However, lately I have been driving my car more often and I have been braking harder.


TESING:

1st Test: I've reviewed the two fuse boxes for any sign of a burnt or blown fuse. = All looks fine.
2nd Test: I've tape the the brake peddle sensor, so it DOES NOT MOVE when I press the brake pedal down. For all intensive purposes, I didn't thing the ABS DCS/TCS would light come on again... BUT! it DID!!

So... maybe its not electrical? maybe its mechanical? - But then why are my brake lights BOTH out right now?

Gyro_Bot

Might possibly be the switch. Even though I kept if from moving when the peddle was pressed.
Its a cheap part, I think I'll gamble and get it swapped. See if it fixes the issue.

Gyro_Bot

NUTS! brand new sensor.... and the problem continues.

Ok, Next I'll take the car to the local repair shop, put in on a lift and check the brake sensors behind each rotor.

Man.... I hope that might be it!

Reoze

If neither of your tail lights are working then you likely have a short in the wiring somewhere. It probably has nothing to do with your wheel speed sensors.

Gyro_Bot

How hard is it to find the short?

Already pulled apart my trunk to look at all the wiring. Nothing stood out, all the wires look secure, no kinks and no loose ends.

Perhaps, there is a tool that might help.

I'm scared to bring my car to a stealership, I'm supporting a family and I can't afford stealership Bull$#!7 charges. Man... a honest mechanic... worth their weight in gold. Its hard to find one!!

Where would you check, if you had this issue?

Reoze

Wiring problems are a bitch. The difficulty could range from "man that was easy" all the way to "I had to rip out the entire interior of my car". If you don't already have the tools and knowledge to figure it out I'd implore you to bring it somewhere. To someone trained to deal with these things, it's generally not a difficult process unless the problem is in a difficult location.

A dealership probably isn't necessary but you'll want to do your homework. There's a lot of horror stories out there about some shops and their inability to fix electrical problems.

Gyro_Bot

All fuses are healthy.
BATTERY:
There is almost negligible parasitic drain on the battery. Looks like just the car brain, peaking around a bit on the Off fuse.

PHYSICAL HARDWARE:
The rear tail lights turn on, when the running lights are enabled. So... it's not a break in the line or both light bulbs blown at the same time. However, they do not respond to the brake pedal.

ROTORS:
Yes rotors do warble a bit on braking... so yeah maybe could replace soon. However they don't warble on normal un breaking travel. So... replacing the rotors can wait... at least for 2 months.

BRAKES:
The brakes seem to respond well and there is no pulling on any side even when heavy or light breaking... so there doesn't seem to be anything sticking. (Like a fused brake calliper)

SENSOR:
The brake pedal sensor (plunger) has been replaced. No change in symptoms.

DASH:
For the Cell on the Dash for both DSC and Traction - they only come on when I depress the brake pedal, and then stay on the rest of the time the car is on.


So.... after a few days to chew on the problem. I'm inclined to think....

Its specific to the brake light function strictly with breaking.

1. Perhaps something to do with the electronic component of the breaking function. A module maybe?

2. MORE LIKELY: While my Blue driver was working is mentioned an "open" and "closed" flag on the real time info screen. This is based on the OBD sensor speaking via bluetooth to my phone. So.... perhaps its simply a short underneath the car that is causing a disconnect between the braking module and the rear tail lights.



Thoughts anyone?
Am I off my rocker.... or.... should I take this to a friendly shop, to let me inspect underneath the car for a pulled or compromised wire running to the back tail lights?
I just don't want to have a shop fumble around and pretend to know what the problem is .... and Charge me up the ****. I can do all those things... except the **** part. I'm very happy putting that money towards new rotors instead.

Reoze

If your brake lights don't come on when you press the pedal then you do in fact likely have a short in your wiring.

Supra1jz

go to harbor freight buy a neg pos terminal tester unplug brake light switch write down which wires or what and whats not powered google wiring chart for connector and if something has power where it shouldn't or doesn't have power you know which line u have to trace for the brake. or which fuse isn't sending power your way

Supra1jz

come by ill put a push button on the shifter for you and when people ask if its your trans brake you can be like nah its my brake my lights -shade tree

Gyro_Bot

On a side note.. the running lights do cause the brake lights to illuminate. However, when I depress the brakes the brake lights do not get any brighter. I agree.... seems like a disconnect somewhere.

On another note... oddly, when I turn on my car there is no issue visible, until I depress the brake pedal and at that moment a the brake pedal does a funny thing... but only once per car start. The brake pedal feels like it does a metal pop - feeling. Like a slight dislocation. Probably the ABS disengaging... I guess.

Just thought I'd mention it.

Gyro_Bot

There is power to the lights when the running lights are turned out (at night). But... yes I can see where this would be useful to work backwards to find that broken wire.

Thanks!

Eric13

Needing assistance with an electrical issue, I currently have my ABS/TSC/DSC lights on. My OBD reader cannot read ABS codes, what places will be able to read these codes? I've had 3 coils fail where they melt and then blow the Engine fuse. First fail was L1, second two have been the T1. My power steering is also not working. I have cleaned all the connections and replaced the harness. With the key to ON position if I press the Brake my lights dim and something resets over and over again. I hear a relay and my head unit resets over and over.

I've fixed/replaced the following since the motor was rebuilt:
Alternator
Battery
Power Steering Harness
Driver Side Window Motor
Cut wire to 3rd brake light
3rd brake light bulb (non LED)
All 4 coils


1.) Make sure none of the wires leading to the sensors have been compromised. Also check the connectors for good secure contact/connection. Have seen many times where due to road debris or when changing out suspension parts that wires have been cut by accident, sensors damaged, or connectors unplugged.

No wires are cut that I can find, nothing appears damaged, nothing is unplugged.

2.) It can always be the sensor itself, just take off the wheels and make sure the sensor is snug, have someone watch your dashboard while you fiddle around with it, if it happens to be loose on a particular side the light on the dash should go away. The sensor is on each hub and is connected with a singular black wire that runs from the body to the sensor(behind the rotor).

Lights stay on even when I fiddle with the sensors. All feel secure.

3.) You can do a RESISTANCE CHECK by: Disconnecting the sensors and checking with an ohmmeter for 0.79 - 2.2k ohms resistance.

I do not have an ohmmeter, but can get one.

4.) Brake light switch could be sticking on the brake pedal. I read where someone replaced it after doing #3 above as he read 4.4 - 4.7ohms at one of the sensors.

I do not have an ohmmeter, but can get one.

5.) Under the hood in the fuse box in location #7 is the ABS/DCS fuse. It's a 60A and you should check this!

Fuse is not blown.

6.) You also need to check #13 a 30A in that same engine bay fuse box.

Fuse is not blown.

7.) In the cabin fusebox(by drivers foot), check #10 which is a 7.5A

Fuse is not blown.

8.) Alignment can cause this issue believe it or not.

Alignment is correct.

9.) A burned out third brake light. Of all things!

All lights are working.

10.) Unfortunately I read that the damn PS connectors being dirty can cause this as well. WTF?

I've cleaned them 4 times with no success.

11.) Oh…I know one………you didn’t stick an LED in the third brake light position did you? That can cause it! I went through that one myself! Some people don't need a load resistor and some do, the value I've seen recommended is........a 2 watt 150 Ohm wire wound resistor. There are some DIY's on how to put it in if you need to do so. Easy to tell, take out the LED and replace with normal bulb and see if issue goes away!

No LEDs.

12.) Get your alternator checked out and make sure it’s not over-charging as this can fry the module.

Replaced alternator 2 months ago.

13.) Keep in mind if the center position of the steering deviates, the DSC may also not operate correctly because there is a sensor in the steering which detects driving conditions. (See reset above, but you might want to check the connector)

Reset does not resolve issue, which connector?

14.) Cut or shorted third brake power wire. This one can pop the 15A stop fuse in the engine bay, so check that!!!!

Fixed a cut to third brake light 2 months ago when I found the light was not working. It fixed the issue originally.

15.) Actually have been cases where just a shorted tail light and/or brake light has caused this and also blown that same 15A stop fuse in the engibe bay.

Fuse is not blown.

16.) Not likely, but the actual switch itself could be bad.

Brake pedal switch?

Gyro_Bot

Ok we found the answer. In this case it was the fuse labelled "STOP".

I didn't notice it the first time I looked through all my fuses, but yes its blown. Even multimeter tested the fuses for parasitic drain (short)
Replaced the fuse, and my tail lights turned back on, got my ABS working again, the CEL disappeared and the traction control CEL also disappeared. Back to normal. All is well.

Seriously.... a 75 cent fuse caused all this trouble?
To test it, I swapped the fuse with another one of equal resistance, so right then and there confirmed it was completely on the fuse, as the reason why this happened.
Damn.... here I was driving around for 4 months trying to find out the short, or the break, or the plug, or the ecu terminal points, or the brake pedal switch, or the tail light bulbs themselves.... and none of those things was the cause.

Just a 75 cent fuse..... man. Definitely should have looked very closely at every single fuse. before moving on. Its the fuse in the main box. Top middle column area.

bbyatv

Tire pressure actually got us on this issue. We have had the DCS and ABS lights on the dash for a long time. We have tried the reset procedure a thousand times it seems like.

It turns out we had a faulty tire pressure gauge that we have been using for years. We just discovered it was putting the tires at 10 psi higher than the reading on the gauge.

Once we discovered the faulty gauge and moved to an accurate one, we set the tires to the proper pressure and were finally able to get rid of the aggravating DCS and ABS lights.

Thanks,
Bruce